Chemically, black carbon or BC is a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter). Black Carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot.Black carbon causes human morbidity and premature mortality.In climatology black carbon is a climate forcing agent. Black carbon warms the Earth by absorbing heat in the atmosphere and by reducing albedo when deposited on snow and ice. Black carbon stays in the atmosphere for only several days to weeks, whereas carbon dioxide (CO2) has an atmospheric lifetime of more than 100 years.The term black carbon is also used in soil sciences and geology, referring either to deposited atmospheric black carbon or to directly incorporated black carbon from vegetation fires. Especially in the tropics, black carbon in soils significantly contributes to fertility as it is able to absorb important plant nutrients.